Updated 4:30 p.m. | The House Ways and Means Committee voted Wednesday in support of launching a criminal investigation into the woman at the center of the IRS scandal — just one day before the Committee on Oversight and Government Reform is set to vote on holding Lois Lerner in contempt of Congress.

In a 23-14 party line vote, the Ways and Means panel approved submission of a formal letter to Eric H. Holder Jr., asking that the attorney general pursue charges against the former IRS official using evidence uncovered during the committee’s year-long investigation.

Wednesday's action — coming after a rare closed-to-the-press meeting — is the latest salvo in what has rapidly escalated into a fiercely partisan battle over the extent to which lawmakers should probe Lerner’s actions. Republicans say Lerner needs to be held to the highest level of accountability. The former IRS official oversaw the agency division responsible for approving groups for tax-exempt status, during which time she allegedly subjected conservative groups to greater scrutiny based on implied party affiliations.

“This investigation has uncovered serious, unprecedented actions taken by Lois Lerner that deprived conservative groups of their rights under the Constitution,” Ways and Means Chairman Dave Camp, R-Mich., said in a statement. “DOJ has a responsibility to act.”

Camp’s 13.5-page letter seeks to make that case. It concludes that Lerner improperly influenced IRS actions against conservative organizations, impeded official investigations into the matter by providing misleading statements to the Treasury Inspector General for Tax Administration and “may have actually disclosed” confidential taxpayer information by using her personal email to conduct official business.

The memo to Holder provides excerpts from internal emails showing that Lerner was inclined from the beginning to deny tax-exempt status to Crossroads GPS, GOP operative Karl Rove’s political nonprofit. The emails quoted in the letter suggest that Lerner did not apply similar scrutiny to liberal-leaning groups.

Democrats, meanwhile, argue that while there might have been serious concerns about Lerner’s involvement early on, Republicans have now turned their investigation into a partisan witch hunt to score political points in an election year.

The Ways and Means Committee on Wednesday debated the letter to Holder in an unusual closed-door executive session that lasted for two hours, a move Democrats fought but on which they were ultimately overruled. Panel member Lloyd Doggett, D-Texas, said afterwards that the committee would release a transcript of the private proceedings in the days ahead, with certain sensitive information redacted.

Ranking member Sander M. Levin, D-Mich., released a copy of his prepared remarks at the start of that executive session. He called the Holder letter redundant, given the Justice Department’s pending investigation into Lerner’s actions and into the IRS scandal overall, and accused Camp of publicizing "previously protected taxpayer information" for political gain.

Releasing a private citizen's tax information is almost unprecedented, Levin said. Ways and Means Democrats believe the last time the panel used confidential taxpayer information in its investigative work was in 1974, and it related to disgraced President Richard M. Nixon.

“I was among the first to call for Lois Lerner to resign and for her to be relieved from her duties,” Levin said. “It now seems clear that Republican members of the Ways and Means Committee have decided that they do not want to be left behind in the Republican campaign to declare this a scandal and keep it going until November.”

Speaking to reporters after the committee reconvened to vote to advance the letter, Camp wouldn’t respond directly to Democrats' charges that the panel's investigation was tantamount to "political theater."

“We have the right and an obligation to protect the American people and we have a right to oversee the IRS and to hold them to account for their actions,” said Camp, who recently announced he would not seek re-election. “Had I gotten documents from the IRS in a timely way, this might have concluded much sooner.”

And as for Crossroads GPS, Doggett suggested that Lerner was probably on the right track in the wake of the 2010 Supreme Court ruling Citizens United, which changed the campaign finance landscape and has also pitted Democrats against Republicans in deploring or lauding the fallout, respectively.

“This is all about Karl Rove,” Doggett told reporters afterwards. “So long as the focus is solely on the IRS and not on Crossroads GPS, Rove wins. It is about whether he can use tens of millions of secret, corporate dollars to pollute our democracy while claiming to be a tax exempt 'social welfare' organization.”